Electrical power distribution systems often include overhead electrical power distribution lines mounted upon poles by a wide variety of mounting structure. Other distribution systems include underground distribution lines in which protected cables run under the ground surface. High voltage phasing meters are designed for use as safety tools by maintenance line workers to verify the status voltage and phase of the grid lines, phase angle between the lines and also phase sequencing. Even though feeder circuits in utility lines are intended to be well balanced in the initial deployment, one of the phases may turn out to be more heavily loaded than others. This leads to load imbalances.
Known high voltage phasing meters comprise high resistance reference and meter probes connected in series with a calibrated panel meter to read the voltage across the phase-to-phase or phase-to-ground terminals. They are designed for use as safety tools by high voltage line maintenance workers to verify the status of the line or equipment as nominal, induced or de-energized. Known devices for providing such measurements include contact type and non-contact cordless type. With contact type a reference probe or transmitter and a meter probe or receiver are connected in series with a cable as the loop is closed with load terminals. With the non-contact cordless type each probe has a meter and the probes close the circuit through wireless means.
The available meters have different features depending on the particular application. These meters may be used for voltage detection, phase measurement, phase sequence identification, and/or testing for induced or live power lines or equipment. For maintenance of overhead power transmission lines, a worker has to reach the live line, hook the probe onto the line, and read the meter to know the status. The probes are very short in length and need to be extended with hot sticks. The line worker holds these hot stick and hooks the meter to the power line for detection and/or measurement. Inadequate lighting and distance from the meter can make it very difficult to read. The meters do not have capacity for storing the diagnostic data for analysis. Even with non-contact cordless type meters, the reading must be taken during maintenance.